1. Field of Invention
The invention relates to internal combustion engines, in particular to true rotary engines in which the energy of combusted gases directly drives rotation of the rotor and whose working members rotate around an axle fixed on a rotor.
2. Discussion of Prior Art
The drawbacks of a conventional internal combustion engine (CICE), in which reciprocal movements of the pistons are translated into rotation of a crankshaft via special transduction means, are well known. The major ones are: 1) low efficiency coefficient due to losses on friction of slide between pistons and cylinders walls and transduction of reciprocal-to-rotational motion; 2) excessive vibrations due to imbalances in the whole piston—transduction mechanism—crankshaft system; 3) big weight; 4) high fuel consumption; 5) necessity for many accessory mechanisms; 6) high environment-polluting propensity. Despite all these considerable drawbacks the CICE for over 100 years continues to be a dominant engine on most types of transportation and non-electrical motor-driven appliances. Moreover, it became the matter of wrongful prestige to bring to the forefront the number of cylinders, liters, valves and largely useless horse powers of such engine. The real alternative to the conventional reciprocal internal combustion engine is rotary internal combustion engine (RICE), in which the energy of expanding gasses directly drives the rotation of the shaft.
Many models of RICE have been proposed and patented. The search of the U.S. Patent Database with the patent's title words query “(((rotary AND internal) AND combustion) AND engine)” resulted in 876 hits, of which about 80% represent new technical solutions. The data on technical testing of the acting prototypes for the most patented RICE models is not available. However, it seems that limited or questionable benefits offered by existing technical solutions of the RICE so far do not justify mass production of any of them, and replacement of the CICE. Most existing models apparently suffer either from excessive complexity translatable into high weight and cost of production or do not provide notable gains in the efficiency coefficient due to inability to reduce leak of gasses among working members. The most advanced model of RICE in terms of industrial elaboration is Wankel engine. The rotor in this type of engine has three convex facets and rotates eccentrically within cylindrical stator with peritrochoidal inner surface. However, this model still suffers from problems in pressurization of the combustion chamber, insufficient durability of compression elements, poor fuel efficiency especially at low loads and enhanced emission of carbohydrates.
Most of the prior arts including authors own one (U.S. Pat. No. 7,077,098, NPC 123/240, July 2006) represent different variations of the vane-type RICE, in which the energy of combusted gasses drives rotation of the rotor via interaction with the vane(s) disposed on the rotor, as such configuration potentially provides the best conditions in terms of energy conversion efficiency. To create working chambers of variable volume required for performing gas compression and expansion cycles the prior arts took advantage of eccentric disposition of the rotor within cylindrical stator (U.S. Pat. No. 1,255,865, NPC 123/235, February 1918; U.S. Pat. No. 2,511,441, NPC 123/235, June 1950, U.S. Pat. No. 3,951,112, NPC 123/242, April 1976; U.S. Pat. No. 3,955,540, NPC 418/260, May 1976; U.S. Pat. No. 3,964,447, NPC 123/236, June 1976; U.S. Pat. No. 4,422,419, NPC 123/235, December 1983; U.S. Pat. No. 4,848,296, NPC 123/242, July 1989; U.S. Pat. No. 6,247,443, NPC 123/229, June 2001) or concentric disposition of the rotor within the stator having peritrochoidlellipsoid-like (U.S. Pat. No. 4,018,191, NPC 123/243, April 1977; U.S. Pat. No. 4,667,468, NPC 123/248, May 1987; U.S. Pat. No. 5,277,158, NPC 123/243, January 1994; U.S. Pat. No. 6,539,913, NPC 123/231, April 2003) or specially shaped (U.S. Pat. No. 1,792,026, NPC 123/235, February 1931; U.S. Pat. No. 4,515,123, NPC 123/222, May 1985; U.S. Pat. No. 5,423,297, NPC 123/213, June, 1995;U.S. Pat. No. 6,070,565, NPC 123/231, June 2000) inner surface together with the vanes movable in radial slots within the rotor while sealingly engaged with the surface of the stator. The spark plug(s) required to ignite compressed air-fuel mixture in all prior arts is placed within the stator's body.
However in many types of vane-type rotary engines the structure is complex due to many components and tangled intrinsic system of gas conduits, and thus manufacturing costs may become high. The reliability and durability of gas sealing mechanisms in existing technical solutions also remains the matter of concern. Most engines also require valves and consequently the additional cumbersome systems for their operation. Thus, simple and yet reliable model of RICE that would attract manufactures attention still remains a priority.